Anyone know if it is possible to drive 4 NEMA 17 Bipolar Stepper Motors from one Arduino Uno? They have four wires each and I am driving them via the L293D H-Bridge Motor Drivers.
I am wanting to control the motors via an IR Controller and have got the following simulation to work on TinkerCAD, however I am unsure how to connect the circuit in real life as the simulation is for DC motors with 2 wires only, not 4.
Do I need 4 L293D Motor Drivers, or can I do it with 2? If so, will there be enough digital pins available? If anyone could help I would be very grateful!
It is for use in a Mecanum Robot so I cannot use my laptop/mains as a power source so I was planning on using 3 x 9V batteries, two as seen in the picture and then one to power the Arduino in the power port.
Those PP3 batteries cannot provide enough current to power the Arduino for long, let alone the motors. Consider using 6 AA batteries in series at the minimum
Ah I see, I just assumed since it worked on the simulation it would be ok. How would I work out the current required? I have attached the motor specs for reference. Is it just 4 motors x 1.7A/phase = 6.8A or since its a bipolar motor is it 2 phases x 4 motors x 1.7A/phase = 13.6A? Or am I incorrect in my thinking?
And where would I need to attach this? Could I just attach it to the breadboard positive/negative rails or should I use it as the Arduino power source?
The ancient L293 is not an appropriate driver for that stepper. They are poor DC motor drivers and even worse stepper drivers. Besides the fact that the L293 is only good for 600mA (on a good day) but the motor is a 1.7 A per phase motor. A more appropriate driver would be a DRV8825. See the Pololu page for how to connect the stepper, driver, Arduino.
You must set the driver coil current limit before using the stepper. See the Pololu page for instructions.
So if I purchase 4 DRV8825 Motor Shields what power supply would I need? The stepper motor has a current rating of 1.7A/phase and a resistance of 1.5Ω/phase, so would I need a maximum 2.55V supply to each motor? Or 5.1V since it is bipolar?
If you could help me understand how to provide the correct amount of power to the circuit that would be a great help. I am having trouble visualising a circuit diagram for it all.
Note that drivers will have a minimum motor power supply voltage requirement (8.2V for DRV8825) and maximum voltage rating (45V for DRV8825). The higher the supply voltage the more torque and speed the motor is capable of.
You can set the current to less than max if the motor does not miss steps. The motor and driver will run cooler and live longer.
24V is a good value. Stepper motors don't have a meaningful voltage specification as they are current driven and stepper drivers are current-output power converters.
Its all about the inductance of the motor windings, the resistance is pretty much irrelevant.
You can use 12V but expect lower top speeds and less dynamic torque. Higher voltages give better top speeds and torques, but every driver has its voltage limit, and efficiency will reduce a bit at higher voltages too.
Any intuition you have from DC motors will not apply to steppers, BTW because of their current-driven nature.
The four motors will need to work with about 6kg of weight applied vertically between them, so will give it a go with a 24V Supply so I get maximum torque.
Erm, I think you need to figure out the torque you actually need as a starting point for sizing any motors. 6kg isn't a torque so the mechanics of the drive mechanism need to be figured out. Steppers are a poor choice for anything but a position control system as they are not efficient.
